Extranodal malignant lymphoma: detection with FDG PET versus CT.
OBJECTIVE
To evaluate use of functional imaging with positron emission tomography (PET) versus computed tomography (CT) for detection of extranodal lymphoma spread.


METHODS
Eighty-one consecutive and previously untreated patients with malignant non-Hodgkin lymphoma (n = 43) or Hodgkin disease (n = 38) were examined with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) PET and contrast material-enhanced CT. Concordant findings at both CT and FDG PET were regarded as actual locations of disease; discordant results were resolved on the basis of biopsy or follow-up results when possible.


RESULTS
Forty-two lesions were identified at both PET and CT, and 19 were verified with biopsy results. PET demonstrated a further 24 lesions. Verification was possible in 15 of these lesions with biopsy (n = 10), magnetic resonance imaging (n = 1), scintigraphic (n = 1), or follow-up (n = 3) results. In 14 of these 15 lesions, PET findings were confirmed (bone marrow, nine; spleen, three; other, two). Seven lesions not visualized at FDG PET were identified at CT, six of which were verified with biopsy (n = 2) or follow-up (n = 4) results. Five of these six CT findings were found to be erroneous. In 13 patients, PET findings led to changes in tumor staging.


CONCLUSIONS
PET may provide more information about extranodal lymphoma than does incremental CT.
Moog
F
F
Department of Nuclear Medicine, University of Ulm, Germany.
Bangerter
M
M
Diederichs
C G
CG
Guhlmann
A
A
Merkle
E
E
Frickhofen
N
N
Reske
S N
SN
D000328:Adult; D001706:Biopsy; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006689:Hodgkin Disease / Q000000981:diagnostic imaging*; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging*; D008297:Male; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18